The invention relates to a method and a face-to-face weaving machine for face-to-face weaving of an upper and a lower fabric, said upper and lower fabric comprising at least a first zone with pile loops, the pile loops being formed around lost pile loop weft yarns, and comprising at least a second zone where no pile loops are formed around lost pile loop weft yarns.
In face-to-face weaving with a face-to-face weaving machine an upper and a lower fabric are simultaneously woven. For weaving fabrics with a loop pile, lost pile loop weft yarns are used to realize the pile loops. Most of the time, the lost pile loop weft yarns are inserted above a spacer which is defining the height of the loop. The lost pile loop weft yarns are removed from the upper and the lower fabric, after having separated the upper and the lower backing fabric, and when the loop pile is combined with the cut pile after cutting through the zones with the pile to be cut (the pile which extends between the lower and the upper fabric).
In face-to-face weaving of an upper and a lower fabric on a face-to-face weaving machine, in which said upper and/or lower fabric comprises at least a first zone with pile loops, where the pile loops are formed around lost pile loop weft yarns, and comprises at least a second zone where no pile loops are formed around lost pile loop weft yarns, the problem claims the attention that when in said second zone in the upper and/or the lower fabric, an area in the weft direction where no pile loops are formed around lost pile loop weft yarns will bridge a considerable length, this lost weft yarn will not be kept by pile loops over this length. This may have several disadvantageous consequences during the weaving process. As far as the upper fabric is concerned, this means that the lost pile loop weft yarns may sag. First of all, this sagging may result in that the lost pile loop weft yarns may get in touch with the lower fabric and may get stuck there. Furthermore, the lost pile loop weft yarns may end up in the reach of the cutting device, because of which they might impede the separation of the upper from the lower fabric. When the loop pile is combined with the cut pile, the cutting process of the pile to be cut may be impeded. Furthermore, excessive wear of the knife may occur, the lost pile loop weft yarns may become stuck between the knife carriage and the guide, the pile loop weft yarn itself may be cut through, because of which it will be impossible to remove it entirely after the upper and the lower fabric have been separated. As far as the lower fabric is concerned, this means that with a combination of loop pile and cut pile in said second zone, where one or several areas occur in the weft direction, where no pile loops are formed around lost pile loop weft yarns, these areas will influence the cutting process of the pile to be cut in the same negative way.
In BE 9900493 a fabric with a combination of cut pile and false boucle is described (forming of loop pile around a weft yarn which is situated on the backing fabric and most of the time is a thick weft yarn). In said patent may be seen that, between 2 pile tufts of the cut pile, false pile loops are formed over the thick weft yarn, in order to avoid that this weft yarn will sag or will hang freely when no pile loops are formed in the weft direction around the various warp yarn systems of a wider zone. The disadvantage of this principle is, that it can only be applied with false loops, as they will lean closely against the backing fabric and will be present unnoticed between the cut pile. However, with a true forming of loops, because of its height and because of its tendency to bend also in the warp direction, the pile loop will not be able to secure the lost weft yarns unnoticed in the same manner.